This invention relates to fuel supply pumps which include a pump rotor and a motor armature assembly, all of which are associated with an axially extending shaft. Adjacent to the electromotor at one end of a housing are mounted two spaced plates between which is mounted a further plate which forms part of the pump assembly. A pump rotor cooperates with the last named plate and, as known, is mounted eccentrically therein and upon rotation thereof serves to feed the fuel from the pump over an electromotor to cool the same while on its path of travel to the internal combustion engine.
Fuel supply units of the known type tent to wear out because of the continuous rotary movement of the rotor elements in the trackway they must follow to perform the function of a pump. This wear is detrimental to pump operation and causes an increase in current consumption as well as a decrease in revolution frequency, quantity of fuel supplied and consequently a reduction in the system pressure, all of which eventually leads to a failure in the fuel supply for the internal combustion engine.